The Ganciclovir and Cidofovir CMV Retinitis Trial (GCCRT) is a study of two treatment regimens that are administered without the use of a central venous catheter for both newly diagnosed and relapsed AIDS-related CMV retinitis. The two regimens are: 1) ganciclovir intraocular device plus oral ganciclovir and 2) intravenous cidofovir. The primary objective of the trial is to compare the newest CMV retinitis drug, cidofovir, to a commonly used treatment regimen, the ganciclovir intraocular device plus oral ganciclovir, with respect to efficacy in preventing vision loss. A secondary objective is to compare a treatment regimen that incorporates highly active local therapy (the ganciclovir device) with a treatment regimen that does not.